Sunday 19 February 2012 14.05 EST
First published on Sunday 19 February 2012 14.05 EST

The public face of the Inland Revenue, the BBC newsreader Moira Stuart, has set up a private firm that allows her to avoid the 50% top rate of tax on some of her income.

The revelation came as the foreign secretary, William Hague, became the first senior cabinet minister to condemn the practice of setting up companies through which to siphon salaries.

The Guardian revealed last week that as many as 25 full-time NHS staff, most on contracts as long as five years, are paid through companies owned by their families. Many were earning well over £100,000 a year. The department of health says it is investigating the position and whether the staff will be allowed to go on the payroll, and the Treasury is undertaking a wider review across Whitehall due to be completed by the end of March.

The device allows individuals to pay as little as 21% corporation tax, rather than the higher rate of 40% or top rate of 50%. Labour has been reluctant to challenge the practice in the NHS since it knows many of the agreements were cleared under the last Labour government.

On the BBC's Andrew Marr programme, Hague said: "I'm not very fond of that sort of behaviour. Sometimes people will have agreed their own arrangements and done it over a long time, and that's their contractual arrangement, so of course they will have their legal rights to that. But, particularly at this time in the nation's history, people should be paying their taxes fully."

Stuart fronts the Inland Revenue's advertising campaign with the catchphrase "tax doesn't have to be taxing" to remind tax-payers to send in their self-assessment tax forms.

The Sunday Telegraph disclosed that Companies House filings reveal she is sole director and shareholder of Moira Stuart Ltd, which was set up in April 2010. The firm's accounts reveals that £22,607 was paid into the company in 2010-11. After £1,749 of administrative expenses, she paid corporation tax on income of £4,380. Had these taxes been subject to income tax, she would have had to pay a bill of over £11,000.

Such service companies have been popular among senior BBC executives for many years, but the scale of their popularity across the public sector is only now becoming clear. They are entirely legitimate for freelancers, but the Inland Revenue is supposed to take action against disguised employees.

Such schemes are advantageous to employers since they may not have to pay national insurance.

It was also reported the chief executive of Britain's largest NHS trust receives his £400,000 salary through a private company that he owns with his wife. The payments are made to Mark Davies, interim chief executive of Iiperial College Healthcare NHS trust Imperial College Healthcare NHS Trust via a company owned by his wife Karen Johnson.

He is described as interim chief executive, but has worked there since May last year. After he was contacted by the Sunday Times, the trust announced that he was to become substantive chief executive, and his payments would be made at source.

The Trust said his appointment followed a lengthy recruitment process that preceded any inquiries by the Sunday Times.

Announcing his permanent appointment on Friday, the trust said in a press release "Since rejoining the Trust last year Mr Davies has taken the Trust from a forecast year end deficit of £35m to one of £19m which includes £44m savings".